TUBE AS 3156764 - Caterpillar

Illustration 1 g00834179
(A-B) Pressure taps for the service brakes. (C) Pressure taps for the accumulators. (1) Rear service brakes. (2) Front service brakes. (3) Position sensor (torque converter impeller clutch). (4) Stop light limit switch. (5) Service brake control valve. (7) Hydraulic oil filter. (8) Accumulators. (9) Parking brake. (10) Pilot relief valve. (11) Accumulator charging valve. (12) Pressure switch (brake accumulator). (13) Pump. (14) Breaker relief valve. (15) Parking brake control valve. (16) Pressure switch (parking brake oil). (18) Hydraulic tank.
Note: The 836H Landfill Compactor is not equipped with rear service brakes.
Illustration 2 g00843539
836H Landfill Compactor Hydraulic Schematic
(B) Pressure tap for the front service brakes. (C) Pressure tap for the accumulator. (2) Front service brakes. (3) Position sensor (torque converter impeller clutch). (4) Stop light limit switch. (5) Service brake control valve. (7) Hydraulic oil filter. (8) Accumulator. (9) Parking brake. (10) Pilot relief valve. (11) Accumulator charging valve. (12) Pressure switch (brake accumulator). (13) Pump. (14) Breaker relief valve. (15) Parking brake control valve. (16) Pressure switch (parking brake oil). (18) Hydraulic tank.
Illustration 3 g01114237
834H Hydraulic Schematic
(A) Pressure tap for the rear brakes. (B) Pressure tap for the front brakes. (C) Pressure taps for the accumulators. (1) Front service brakes. (2) Rear service brakes. (3) Position sensor (torque converter impeller clutch). (4) Stoplight switch. (5) Service brake control valve. (6) Temperature sensor. (7) Hydraulic oil filter. (8) Accumulators. (9) Parking brake. (10) Pilot relief valve. (11) Accumulator charging valve. (12) Pressure switch (brake accumulator). (13) Pump. (14) Breaker relief valve. (15) Parking brake control valve. (16) Pressure switch (parking brake oil). (18) Hydraulic tank.
Oil is sent from pump (13) through accumulator charging valve (11) into the oil end of the accumulators (8). A piston in the accumulator is held by dry nitrogen gas at a pressure of 5520 350 kPa (800 50 psi).Oil flows into the accumulator in order to move the piston against the dry nitrogen. This compresses the dry nitrogen until the oil pressure reaches 14973 345 kPa (2172 50 psi) for the 834H or 14485 345 kPa (2100 50 psi) for the 836H. The oil also flows to the brake control valve (5) and to the pressure switch (12). The pressure switch will remain in the normally closed position. The low brake pressure indicator will remain illuminated until the oil reaches a pressure of 8960 537 kPa (1300 78 psi). This pressure is also sensed in accumulator charging valve (11) which stops the flow of oil to the accumulator.A check valve in the accumulator charging valve prevents oil from flowing back through the charging valve. The flow control valve in the accumulator charging valve controls maximum oil pressure to the accumulator if the charging valve spool does not work correctly.Brake control valve (5) is for the service brakes. Brake control valve (5) is in the circuit from the accumulator to the service brakes. When either brake pedal is pushed, oil from the accumulator flows to the brakes.After the